Apparatus for conveying envelope blanks through the seal flap adhesive drying section of an envelope making machine

ABSTRACT

Envelope blanks arranged in overlapped relation with the seal flap portions exposed are conveyed past a seal flap gummer mechanism where a roll applicator continuously applies a liquid gum adhesive to the seal flap portions of the envelope blanks. The overlapped envelope blanks are slightly separated to space the portions of the seal flaps having the wet adhesive thereon to prevent the blanks from adhering to each other. The overlapped and slightly separated envelope blanks are then conveyed by two pairs of endless chains through the drier section of the envelope machine to dry the wet seal flap adhesive. Each pair of endless chains has an upper chain with a conveying section positioned in juxtaposition with the upper conveying section of the lower chain. The pairs of chains are positioned in spaced parallel relation and the respective conveying sections frictionally engage the side flap portions of the envelope blanks therebetween and convey the overlapped blanks through the drier section. The chains have laminated block links connected to adjacent lines by pairs of link plates. Both the link and link plates have a generally planar or flat surface and an upper arcuate surface with raised end portions and a recessed intermediate portion. The chains formed from the link blocks and link plates thus have a generally flat surface and a curved surface with outwardly extending spaced, raised portion. The conveying section the the upper chains have the curved surface with the spaced, raised portions engaging the overlapped envelope blanks and the conveying sections of the lower chains have the flat surface engaging the envelope blanks. The lower chains are coated with a silicone rubber to increase the friction between the envelope blanks and the conveying section of the chains without marking the envelope blanks and preventing the envelope blanks from slipping during transport through the drier section.

United States Patent Helm [ 51 May 30, 1972 [54] APPARATUS FOR CONVEYING ENVELOPE BLANKS THROUGH THE SEAL FLAP ADHESIVE DRYING SECTION OF AN ENVELOPE MAKING MACHINE [72] Inventor: Herbert W. Helm, Hollidaysburg, Pa.

[73] Assignee: F. L. Smlthe Machine Company, Inc.,

Duncansville, Pa.

[22] Filed: Sept. 17, 1970 [211 App]. No.: 73,118

l-libbard Lathrop. Coy Potdevin 271/45 UX 271/45 UX Primary Examiner-Joseph Wegbreit Attorney-Stanley J. Price, Jr.

[5 7] ABSTRACT Envelope blanks arranged in overlapped relation with the seal flap portions exposed are conveyed past a seal flap gummer mechanism where a roll applicator continuously applies a liquid gum adhesive to the seal flap portions of the envelope blanks. The overlapped envelope blanks are slightly separated to space the portions of the seal flaps having the wet adhesive thereon to prevent the blanks from adhering to each other. The overlapped and slightly separated envelope blanks are then conveyed by two pairs of endless chains through the drier section of the envelope machine to dry the wet seal flap adhesive. Each pair of endless chains has an upper chain with a conveying section positioned in juxtaposition with the upper conveying section of the lower chain. The pairs of chains are positioned in spaced parallel relation and the respective conveying sections frictionally engage the side flap portions of the envelope blanks therebetween and convey the overlapped blanks through the drier section. The chains have laminated block links connected to adjacent lines by pairs of link plates. Both the link and link plates have a generally planar or flat surface and an upper arcuate surface with raised end portions and a recessed intermediate portion. The chains formed from the link blocks and link plates thus have a generally flat surface and a curved surface with outwardly extending spaced, raised portion. The conveying section the the upper chains have the curved surface with the spaced, raised portions engaging the overlapped envelope blanks and the conveying sections of the lower chains have the flat surface engaging the envelope blanks. The lower chains are coated with a silicone rubber to increase the friction between the envelope blanks and the conveying section of the chains without marking the envelope blanks and preventing the envelope blanks from slipping during transport through the drier section.

10 Claims, 6 Drawing Figures PATENTEUMAY 30 I972 SHEET 1 OF 2 PATENTED MAY 3 0 I972 sum 2 or 2 APPARATUS FOR CONVEYING ENVELOPE BLANKS THROUGH THE SEAL FLAP ADHESIVE DRYING SECTION OF AN ENVELOPE MAKING MACHINE BACKGROUND OF THE INVENTION 1. Field of the Invention This invention relates to apparatus for conveying envelope blanks through a drier in an envelope machine and more particularly, to pairs of abutting endless chains for engaging opposite surfaces of envelope blanks with one or more of the chains coated with a friction increasing material.

2. Description of the Prior Art In the past, overlapped envelope blanks with wet seal flap adhesive thereon were conveyed through the drier section of an envelope machine by endless fabric tapes or belts, or by endless chains having separate clips for each envelope blank or, as disclosed in U.S. Pat. No. 3,021,6l0, by pairs of endless chains having separate resilient gripping blocks secured to each link of the chain with opposed gripping blocks engaging the surfaces of the overlapped envelope blanks. The fabric belts have a tendency to stretch and do not exert a uniform engaging force on the blanks and frequent slippage of the blanks occurs during transport. The spring clips on the endless chains limit the speed of the envelope machine and are frequently torn off from the chain and cause jamming of the envelope machine. The resilient pads secured to each link of overlying chains also were frequently torn OE and caused jamming of the machine. To prevent such malfunctions, frequent inspections of the drier chains were necessary to replace and further secure the clips or resilient blocks to the chains. There is a need for conveying apparatus for the blanks that is durable, inexpensive, maintenance free and does not permit slippage of the blanks during transport through the drier section of the envelope machine.

SUMMARY OF THE INVENTION In accordance with the resent invention, the apparatus for conveying overlapped envelope blanks through the drier section of an envelope making machine includes a pair of upper endless chains and a pair of lower endless chains. The upper chains are in parallel, spaced relation and have lower conveying sections. The pairs of lower chains are in underlying relation with the upper chains and have upper conveying sections in juxtaposition with the lower conveying sections of the pair of upper chains. The conveying sections of both pairs of chains are supported so that they remain in frictional engagement with the overlapped envelope blanks therebetween. At least one of the pairs of chains have the surface of the chain that engage the envelope blanks coated with a material having a coefficient of friction greater than the coefficient of friction of the chain surface. Silicone rubber has been found suitable as the coating material. The coated chains are relatively maintenance free and do not have separate elements secured thereto that may be torn off and cause the machine to jam and malfunction. The coated chains convey the overlapped envelope blanks without the blanks slipping in transport.

Accordingly, the principal object of this invention is to provide conveying apparatus for overlapped envelope blanks that include chains without separate blank engaging elements secured thereto.

Another object of this invention is to provide endless chain type conveyors for overlapped envelope blanks that are maintenance free and do not cause malfunctions in the envelope making machine.

These and other object and advantages of this invention will be more completely disclosed and described in the following specification, the accompanying drawings and the appended claims.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a fragmentary, schematic drawing, in elevation, of an envelope making machine illustrating the various components of the machine, the drier section and the apparatus for conveying the envelope blanks through the drier section.

FIG. 2 is an enlarged, fragmentary view, in section, of the envelope machine drier section with the envelope blank conveying apparatus positioned above the drying elements.

FIG. 3 is a view in section taken along the line III-III of FIG. 2 illustrating the support means for the conveyor sections of the conveyor chains.

FIG. 4 is an enlarged view, in section, illustrating a portion of the conveyor chains conveying sections.

FIG. 5 is a top plan view, in section, taken along the line V-V of FIG. 3 illustrating the overlapped envelope blanks being transported through the drier section by the endless conveyor chains.

FIG. 6 is a view in section, taken along the line VI-VI of FIG. 4, illustrating the envelope blank frictionally engaged by the surfaces of the conveyor chains.

DESCRIPTION OF THE PREFERRED EMBODIMENT Referring to the drawings, and particularly to FIG. 1, there is illustrated an envelope making machine generally designated by the numeral 10 that has feeder-printer section 12, a delivery and drier section 14, a folder section 16 and an aligner section 18. The envelope blanks are fed from a rotary feeder 20 through a printer unit to a panel cutter where panels are cut in separate envelope blanks and an adhesive is applied around the window or panel portion of the blank. Thereafter, the envelope blanks are transferred to a collator section, not shown, where glassine patches are applied to the envelope blanks while on the collator roll. Thereafter, the envelope blanks are positioned in overlapped relation and conveyed past an applicator roll where a liquid adhesive is applied to a seal flap portion of the envelope blanks. Thereafter, the envelope blanks are slightly separated and fed in the slightly separated and overlapped relation, to conveying apparatus for conveying the overlapped envelope blanks, with the wet adhesive thereon, through the drying section 14, where the seal flap adhesive is dried. A schematic illustration of the abovediscussed apparatus is disclosed in copending U.S. patent application Ser. No. 51,754, filed on July 2, 1970, entitled METHOD AND APPARATUS FOR CONTROLLING THE HEAT INTENSITY OF AN ENVELOPE MACHINE DRI- ER.

The drier section 14 has a plurality of quartz lamps 22 that supply heat for drying the liquid adhesive on the seal flap portion of the overlapped envelope blanks. The envelope blanks are conveyed through the drier section by two pairs of endless chains. The upper pair of endless chains will be generally designated by the numeral 24 and the lower pair of endless chains will be designated generally by the numeral 26. The upper pair of endless chains 24 are reeved at one end about drive sprockets 28 and the lower pair of endless chains are reeved about drive sprockets 30 in the aligner section 18. Suitable idler sprockets are provided adjacent to the conveyors from the seal flap gummer and suitable tension sprockets or pulleys are also provided to maintain the desired tension on the endless chains 24 and 26.

The upper pairs of endless chains 24 have a lower conveying section 32 that is supported in elongated channel supports 34. The channel supports 34 have the leg portions extending downwardly and the upper portion of the conveying section 32 abut the web portion of channels 34. The return section of the conveyor chains 24 are suitably supported on support rollers 36 to reduce the catenary effect of the long span of con veyor chain return run.

The lower conveyor chains 26 have an upper conveyor section 38 and a return section 40. The upper conveyor section 38 is supported in upwardly facing channel members 42 to maintain the conveying sections 32 and 38 in juxtaposition with the envelope blanks therebetween. The return run of the lower conveyor chains 26 are suitably supported by roller sprockets 44 and the support members are movable laterally for different size envelope blanks.

Referring to FIG. 3, the adjustable supports generally designated by the numeral 46 are illustrated and include a first arm member 48 threadedly positioned on an adjusting shaft 50. A similar support arm 52 is threadedly supported on an oppositely threaded portion of shaft 50. With this arrangement, rotation of shaft 50 by means of the gearing 54 moves the arm members 48 and 52 toward and away from each other and thus, control the portion of the envelope blank that is engaged by the conveyor sections 32 and 38 of the pairs of conveyor chains 24 and 26. With this arrangement, different size envelope blanks are engaged at their side flap portions by the chain conveyor sections 32 and 38 as is illustrated in FIG. 5.

Referring to FIGS. 4 and 6, the construction of the respective chains 24 and 26 are illustrated in detail. The chain members have laminated block portions 56 that are connected to adjacent block portions 56 by a pair of side link plates 58. Rivets 60 engage the link plates 58 to the laminated blocks 56 as is illustrated in FIGS. 4 and 6. The laminated blocks 56 have a relatively flat planar upper surface 62 and an arcuate lower surface 64 that has a pair of outwardly extending end portions 66 and 68 with a recessed intermediate portion 70. The link plates 58 have a similar upper planar flat surface 72 and an arcuate lower surface 74 with a pair of outwardly extending end portions 76 and 78 with an intermediate recessed portion 80 therebetween. When the laminated blocks 56 are secured to adjacent laminated blocks by the link plates 58, the chain members have a relatively flat first surface generally designated by the numeral 82 in FIG. 2, and an arcuate surface generally designated by the numeral 84 with the raised portions 76 and 78 of the link plates and the raised portions 66 and 68 of the laminated blocks forming outwardly extending spaced raised portions on the surface 84.

The upper pair of endless chains are positioned on the drive sprockets 28 so that the conveying section 32 has the relatively flat planar portion 82 abutting the underside of the support members 34 and the arcuate portion with the outwardly extending spaced raised portion 84 extending downwardly toward the lower conveying section 38 of the lower pairs of chains 26. The pair of lower chains 26 are positioned on the sprockets so that the conveying section 38 has the planar or flat surface 82 extending upwardly into juxtaposition with the downwardly extending raised portions of the upper conveying section 32 of the upper pairs of chains 24. With this arrangement, the lower conveying section 38 of the chains 26 form a relatively flat planar surface 82 that engages the bottom side of the envelope blank. The upper conveying section 32 has the downwardly depending raised portions that engage the top surface of the envelope blanks.

The pairs of lower chains 26 are coated with a friction increasing material, as for example, silicone rubber to increase the coefficient of friction of the chain as compared with the coefficient of friction of the uncoated chain. lt has been found, when at least one pair of the conveyor chains has the surface that engages the overlapped envelope blanks coated with the silicone rubber, the co-efiicient of friction between the envelope blanks and the conveyor chain is increased to an extent that the blanks do not slip while being conveyed or transported by the pairs of conveyor chains 24 and 26. The thickness of the coating material is not critical; it is preferred, however, that the coating material be relatively thin. The coating material should be stable and servicable at elevated temperatures and resistant to oxidation in the presence of heat. The coating material should be easily bonded to the metallic chain and the bond remain between the coating material and the chain for long periods of time. The silicone rubber has been found to be an excellent coating material that provides the desired increase in the coefficient of friction for at least one pair of the conveyor chains to prevent slippage between the chains and the overlapped envelope blanks as the blanks are transported through the drier section 14.

Referring to FIG. 5, the manner in which the overlapped blanks are transported through the drier section is illustrated. The overlapped envelope blanks are transported with the liquid seal flap adhesive facing downwardly and the envelope blanks are engaged by the chain conveyor sections 32 and 38 along the side flap portions at a suitable distance laterally, from the wet adhesive seal flap portion.

For example, in FIG. 5, the overlapped envelope blanks have side flap portions 92 and 94 while the liquid adhesive on the seal flap portion 96 is dried by the heat from the quartz drying lamps 22.

It has been found that with at least one pair of the conveyor chains coated with the friction increasing material, it is now possible to convey the overlapped envelope blanks without the use of resilient blocks secured to the chain links or without separate metallic clips to engage each of the envelope blanks separately. The coating on the conveyor chains remains stable and adheres to the conveyor chain links to provide adequate friction for engagement of the overlapped envelope blanks.

According to the provisions of the patent statutes, I have explained the principle, preferred construction and mode of operation of my invention and have illustrated and described what I now consider to represent its best embodiment. However, it should be understood that, within the scope of the appended claims, the invention may be practiced otherwise than as specifically illustrated and described.

I claim:

1. Apparatus for conveying envelope blanks in overlapped relation through a drier section of an envelope machine comprising,

a pair of upper endless chains positioned in spaced substantially parallel relation to each other, a portion of each of said pair of upper endless chains forming a lower conveying section,

a pair of lower endless chains positioned in spaced substantially parallel relation to each other and each of said lower endless chains positioned in underlying relation to one of said upper endless chains,

a portion of each of said lower endless chains forming an upper conveying section positioned in juxtaposition with said lower conveying section of said respective upper endless chains,

means to support said upper and lower conveying sections of said chains and maintain said conveying section portions of said chains in frictional engagement with envelope blanks therebetween,

means to move said upper and lower conveying sections through said drier section in timed relation to each other to convey said overlapped envelope blanks at a preselected speed, and

at least one of said pair of chains having the surface of said portions forming a conveying section of said chain in engagement with said envelope blanks coated with a material having a coefficient of friction greater than the coefficient of friction of said surface of said chain.

2. Apparatus for conveying envelope blanks as set forth in claim 1 in which,

said surface of said chains is coated with silicone rubber.

3. Apparatus for conveying envelope blanks as set forth in claim 1 in which,

said surface of said pair of lower chains being coated with said material.

4. Apparatus for conveying envelope blanks as set forth in claim 1 in which,

one of said pair of chains having a relatively flat planar surface for engagement with said overlapped envelope blanks,

the other pair of said chains have a surface with spaced, raised portions for engagement with said overlapped envelope blanks.

5. Apparatus for conveying envelope blanks as set forth in claim 4 in which,

said flat surface of said pair of chains is coated with said material.

6. Apparatus for conveying envelope blanks as set forth in claim 1 in which,

at least one of said pairs of said chains includes block link members connected to adjacent link members by a pair of link plates,

said block link members having a flat planar first horizontal 8. Apparatus for conveying envelope blanks as set forth in surface and an opposite second horizontal arcuate surclaim 7in which, face with raised end portions and a recessed intermediate said lower conveying section of said lower endless chains portion, having said flat surface extending upwardly into engagesaid link plates having a flat planar first horizontal surface 5 m n! wi h he o om surface of said overlapped enand an opposite second horizontal arcuate surface with ope nk raised end portions and a recessed intermediate portion, 9. Apparatus for conveying envelope blanks as set forth in said link blocks and link plates connected with said flat surclaim 8 in which,

faces in the same horizontal plane and forming a first rela- Said pp Conveying Section of Said "PP" endless chain tively flat planar surface and a second curved surface with 10 having said Surface with Said spaced raised Portions outwardly extending spaced raised portion tending downwardly in engagement with the top surface 7. Apparatus for conveying envelope blanks as set forth in ofsaid overlapped envelope blanksclaim 6 in which, 10. Apparatus for conveying envelope blanks as set forth in both of said pairs of chains having said first relatively flat Clair? which planar Surface and Said Second curved Surface with said pair of lower chains being coated with silicone rubber.

wardly extendingspaced raised portions. 

1. Apparatus for conveying envelope blanks in overlapped relation through a drier section of an envelope machine comprising, a pair of upper endless chains positioned in spaced substantially parallel relation to each other, a portion of each of said pair of upper endless chains forming a lower conveying section, a pair of lower endless chains positioned in spaced substantially parallel relation to each other and each of said lower endless chains positioned in underlying relation to one of said upper endless chains, a portion of each of said lower endless chains forming an upper conveying section positioned in juxtaposition with said lower conveying section of said respective upper endless chains, means to support said upper and lower conveying sections of said chains and maintain said conveying section portions of said chains in frictional engagement with envelope blanks therebetween, means to move said upper and lower conveying sections through said drier section in timed relation to each other to convey said overlapped envelope blanks at a preselected speed, and at least one of said pair of chains having the surface of said portions forming a conveying section of said chain in engagement with said envelope blanks coated with a material having a coefficient of friction greater than the coefficient of friction of said surface of said chain.
 2. Apparatus for conveying envelope blanks as set forth in claim 1 in which, said surface of said chains is coated with silicone rubber.
 3. Apparatus for conveying envelope blanks as set forth in claim 1 in which, said surface of said pair of lower chains being coated with said material.
 4. Apparatus for conveying envelope blanks as set forth in claim 1 in which, one of said pair of chains having a relatively flat planar surface for engagement with said overlapped envelope blanks, the other pair of said chains have a surface with spaced, raised portions for engagement with said overlapped envelope blanks.
 5. Apparatus for conveying envelope blanks as set forth in claim 4 in which, said flat surface of said pair of chains is coated with said material.
 6. Apparatus for conveying envelope blanks as set forth in claim 1 in which, at least one of said pairs of said chains includes block link members connected to adjacent link members by a pair of link plates, said block link members having a flat planar first horizontal surface and an opposite second horizontal arcuate surface with raised end portions and a recessed intermediate portion, said link plates having a flat planar first horizontal surface and an opposite second horizontal arcuate surface with raised end portions and a recessed intermediate portion, said link blocks and link plates connected with said flat surfaces in the same horizontal plane and forming a first relatively flat planar surface and a second curved surface with outwardly extending spaced raised portions.
 7. Apparatus for conveying envelope blanks as set forth in claim 6 in which, both of said pairs of chains having said first relatively flat planar surface and said second curved surface with outwardly extending spaced raised portions.
 8. Apparatus for conveying envelope blanks as set forth in claim 7 in which, said lower conveying section of said lower endless chains having said flat surface extending upwardly into engagement with the bottom surface of said overlapped envelope blanks.
 9. Apparatus for conveying envelope blanks as set forth in claim 8 in which, said upper conveying section of said upper endless chain having said surface with said spaced raised portions extending downwardly in engagement with the top surface of said overlapped envelope blanks.
 10. Apparatus for conveying envelope blanks as set forth in claIm 9 in which, said pair of lower chains being coated with silicone rubber. 